Make accumulate! compatible with offset indices

Author: Andy Ferris

base/accumulate.jl

@@ -383,10 +383,10 @@ function _accumulate1!(op, B, v1, A::AbstractVector, dim::Integer)
     inds = LinearIndices(A)
     inds == LinearIndices(B) || throw(DimensionMismatch("LinearIndices of A and B don't match"))
     dim > 1 && return copyto!(B, A)
-    i1 = inds[1]
+    i1 = first(inds)
     cur_val = v1
     B[i1] = cur_val
-    @inbounds for i in inds[2:end]
+    @inbounds for i in inds[2:end] # Range getindex of offset slices is inconsistent with scalar indexing of offset slices
         cur_val = op(cur_val, A[i])
         B[i] = cur_val
     end